Nissan introduces series-hybrid powertrain with Note e-POWER in Japan; small pack, small engine, LEAF motor, low price
In Japan, Nissan Motor introduced its new series-hybrid drive system called e-POWER along with its application in the Note. This marks the first availability of e-POWER technology for consumers, marking a milestone in the electrification strategy under Nissan Intelligent Mobility.
e-POWER borrows from the EV technology in the Nissan LEAF. Unlike the all-battery-electric powertrain of the LEAF, e-POWER adds a small gasoline engine to charge the high-output battery when necessary, eliminating the need for an external charger while offering the same high-output. Nissan says that although e-POWER uses a much smaller battery than the LEAF (1.5 kWh vs 30 kWh), it delivers the same driving experience as a full EV.
Chief powertrain engineer Naoki Nakada says minimizing battery size and compartmentalizing powertrain components to fit a compact vehicle were the first challenges.
Compared to LEAF, the batteries are 1/20th the size and made to fit under the front seats without having to sacrifice interior space.—Naoki Nakada
|Differences between powertrains. Click to enlarge.|
The e-POWER system features full electric-motor drive—the wheels are completely driven by the electric motor—the EM57 traction motor from the LEAF—which delivers a maximum 254 N·m from 0-3008 rpm. The power from a high-output battery is delivered to the e-POWER’s compact powertrain comprising a gasoline engine, power generator, inverter, and a motor.
The engine is the 1.2-liter, three-cylinder HR12DE. In general a three-cylinder engine tends to be louder and with more vibration than a four-cylinder engine. Nissan used an outer balancer to reduce vibration and noise, achieving quietness equivalent to that of a four-cylinder engine.
In conventional hybrid systems, a low-output electric motor is mated to a gasoline engine range extender to drive the wheels when the battery is low (or when traveling at high speeds). However, in the e-POWER system, the gasoline engine is not connected to the wheels; it simply charges the battery. Unlike a full EV, the power source originates from the engine and not just the battery.
e-POWER delivers massive torque almost instantly, which enhances drive response and results in smooth acceleration. Also, the system operates very quietly, much like a full EV. Because e-POWER relies on the engine much less frequently, its fuel efficiency is comparable to that of leading conventional hybrids, especially during around-the-town commutes.
Nissan is offering the Note e-POWER to its Japanese customers in three trim levels: S, X and Medalist. Fuel economy on the JC-08 cycle is 37.2 km/L (87 mpg US, 2.69 L/100km); 34.0 km/L (80 mpg US, 2.94 L/100km); and 34.0 km/L, respectively. Pricing for the entry-level S-trim starts at ¥1,772,280 (US$16,900).
Development History. Nissan is actively pursuing a zero-emission, zero-fatality world for driving through its EV program and autonomous drive technology. To make this vision a reality, Nissan is developing “Nissan Intelligent Mobility,” which anchors critical company decisions around how cars are powered, how cars are driven, and how cars integrate into society, all while staying focused on creating more enjoyable driving experiences.
In 2006, Nissan’s engineers were able to reduce the battery capacity to match its competitors’ hybrid vehicles while still delivering desirable EV qualities, such as quietness and efficient energy use. In addition, application of Nissan’s technologies, such as the integration of a power-generating engine, electric motor drive for compact car use, strengthening of the powertrain’s rigidity and improvements in NVH levels, became the foundation of e-POWER and its implementation in the compact-car segment.
Nissan is committed to developing electric-powered powertrains that use various fuels to cater to the different requirements of the world’s markets. e-POWER is but one example of that quest and will strengthen Nissan’s lineup of electric-powered powertrains. Nissan is also conducting research and development of the SOFC (Solid Oxide Fuel Cell) fuel-cell vehicle.
At the SAE 2016 Range Extenders for Electric Vehicles Symposium starting today in Knoxville, TN, Nissan will present a usability study of a fuel cell range extended EV (FC-REEV). Nissan has developed powertrain systems models to simulate usability issues—such as charging time—for BEVs and FC-REEVs.